Double orthodontia formulas and Lascoux positivity
Speaker:
Linus Setiabrata (University of Chicago)
Date and Time:
Friday, January 31, 2025 - 3:30pm to 5:00pm
Location:
Fields Institute, Room 210
Abstract:
Motivated by our search for a representation-theoretic avatar for double Grothendieck polynomials, we give a new formula for these polynomials based on Magyar's orthodontia algorithm for diagrams. We obtain a similar formula for double Schubert polynomials, and a curious positivity result: the polynomial xn1…xnnSw(x−1n,…,x−11;1,…,1) is a graded nonnegative sum of Lascoux polynomials. Joint work with Avery St. Dizier.